He was taken to Dell Seton Medical Center with critical, potentially life-threatening injuries by STAR Flight.

According to ATCEMS, emergency responders were called at the Reimers Ranch Park on Hamilton Pool Road after two adult swimmers did not resurface while swimming in the Pedernales River.

After arriving on scene, first responders were able to locate and remove one swimmer from the river. First responders searched Pedernales River for over 30 miniutes for the second swimmer before transitioning their rescue efforts into recovery mode.

According to the Travis County Sheriff's Office, the two swimmers were brothers.

The brothers were attempting to cross Pedernales River, which can reach up to twelve feet deep in some places. While swimming across, one of the brothers went into distress. The second brother attempted to help before going underwater himself. He stayed under for about two to three minutes before witnesses along the river were able to find and rescue him.

"We hate it when things like this happen. This is a time when it should be a whole lot of fun and people should be out enjoying our beautiful country with their families, and tragedy strikes. To our knowledge, this young man was not wearing a flotation device," said TCSO Senior PIO Kristen Dark.

This is a developing story and will be updated with more information as it becomes available.